Scale base



FIG. 1 is a top, front, and left side perspective view of a scale base showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a rear elevational view;

FIG. 4 is a top plan view;

FIG. 5 is a bottom plan view;

FIG. 6 is a right side elevational view;

FIG. 7 is a left side elevational view;

FIG. 8 is a front elevational view, with the display screen showing typical indicia thereon; and

FIG. 9 is a left side elevational view thereof, with the display screen showing typical indicia thereon. 

The ornamental design for scale base, as shown. 